It has become popular to provide shower heads which can be used either as a normal shower head or as a massaging, i.e., pulsating, shower head. In designing such a shower head, it is necessary to have some method of "chopping" the stream of water to give the pulsating effect; and the chopped stream of water should be emitted from the shower head through relatively large holes to produce "bulk" in the pulsed water and, therefore, a better massage-type feeling. The shower head should also have an alternate steady-stream flow; there the water preferably passes through small holes to give a finer stream. Thus, it is better to have two sets of outlet holes and some control means for directing the stream of water to one or the other of the sets. In addition, there should be some method of "chopping" the water passing out of the large holes.
The prior art patents include a variety of pulsing techniques. One approach is to direct the incoming water to different flow passages to provide two flows of water. One flow goes through the chopping blade of a turbine, and the other bypasses the chopping blade and is a steady-state flow. The nature of the outlet water flow is determined by controlling the amount of flow through the passages. Another approach is to divide all the water into two paths, one through a cylindrical chopping unit operated by a turbine and the other through a by-pass. The water then goes through a valve controlling the output from the paths and then into a plenum chamber and to outlets. All of the water, whether pulsed or steady, passes through the same outlet openings.
Prior art patents relating to this field include:
______________________________________ 1,609,047 Beale 2,878,066 Erwin 3,473,736 Heitzman 3,568,716 Heitzman 1,101,804 Lauder 3,801,019 Trenary et al. 3,920,185 Kwok. ______________________________________
In my U.S. Pat. No. 3,963,179 issued June 15, 1976, I have described yet another approach toward producing pulsating and steady-state streams of water for a shower head. There, all of the incoming water enters a common plenum chamber which contains a rotor or spinner, rotated by the incoming water. The spinner has chopping vanes which alternately open and close one or more exit openings from the plenum chamber so that all of the water leaving the plenum is "chopped" or pulsed. The water may then either leave the shower head directly to produce a pulsating spray or may be led through depulsing channels to fine outlet openings for a steady spray.
The present invention is a change over my earlier invention in that the water flow entering and leaving the plenum chamber affects the speed of rotation of the rotor and so affects the extent of the chopping of the exiting water. This enhances the efficiency of the unit both by increasing the sharpness of the pulsed spray and also by improving the steadiness of the steadystate spray. Under some circumstances the user may find this control means sufficient by itself to produce pulsating and steady-state sprays of a type satisfactory for normal use.